Rotary shaft drilling apparatus

ABSTRACT

The apparatus has a frame and a carriage assembly. Hydraulic thrust cylinders are employed to raise and lower the carriage assembly relative to the frame. A rotary table supported by the carriage assembly moves up or down with the carriage assembly and can be pivoted about a generally horizontal axis, relative to the frame and carriage assembly. The method is carried out by pivoting the rotary table into alignment with a generally horizontally oriented drill string section, coupling the drill string section to the rotary table, moving the rotary table to generally vertically orient the drill string section in drilling alignment, and lowering and rotating the drill string to penetrate the formation. Drill string sections are aligned for addition in the same way. Drill string is removed by reversing the procedure.

' United States Patent 151 3,695,363 Kelly, Jr. 1 Oct. 3, 1972 ROTARY SHAFT DRILLING Primary Examiner-Ernest R. Purser APPARATUS Attorney-Robert A. Felsman 72 Inventor: Jose h L. Kell ,Jr., H st ,T l 1 p y ex 57 ABSTRACT [73] Assigneec Hughes Tool Company, Houston,

The apparatus has a frame and a carriage assembly. Hydraulic thrust cylinders are employed to raise and [22] Fled: Sept 1970 lower the carriage assembly relative to the frame. A [21] App], NO Z 75,025 rotary table supported by the carriage assembly moves up or down with the carriage assembly and can be pivoted about a generally horizontal axis, relative to {iii iii'ifiii:I31313::jiiiiiiiiiiiiTflffl131155;;Z3733 thefmandcamageassembly' [58] Field of Search 173/1, 42, 43; 175/52, 57, The method is carried out by pivoting the rotary table l /8 into alignment with a'generally horizontally oriented drill string section, coupling the drill string section to References cued the rotary table, moving the rotary table to generally UNITED STATES PATENTS vertically orient the drill string section in drilling alignment, and lowering and rotating the drill string to Homamck X penetrate the formation string sections are 3,460,638 8/1969 Millsapps .....l75/85 aligned addition in the Same way. Dril] string is removed by reversing the procedure.

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FIGURE 1 PATENTEDuma I972 SHEET '2 or 5 FIGURE 3 FIGURE 2 JOSEPH L. KELLY, JR.

1 N VEN TOR.

PATENTED T 3 I972 SHEET 3 BF 5 FIGURE 4 all;

gillig JOSEPH L. KELLY, JR.

I N VEN TOR.

PATENTEDnm m2 SHEET 5 BF 5 FIGURE 10 FIGURE 7 JOSEPH L. KELLY, JR.

1 N VEN TOR.

1 ROTARY SHAFT DRILLING APPARATUS BACKGROUND OF THE INVENTION cable and traveling block or some similar assembly to,

hoist drill string sections into vertical orientation for coupling to the rotary table. Further, in instances where hydraulic lift means are utilized, as in US. Pat. No. 3,460,638, rigid frame means have been provided for purposes including protection of the hydraulic lift cylinders, which ordinarily cannot withstand extensive misalignment.

US. Pat. Nos. 3,460,638; 3,454,114; 2,979,320; 3,231,029; 3,266,582 and, 3,220,494 generally illustrate such devices.

SUMMARY OF THE INVENTION This invention contemplates a rotary shaft drilling apparatus and method with which the rotary drive assembly is brought to the racked drill string sections for coupling and the rotary drive and coupled section is thereafter moved into drilling alignment. As a result, drill string coupling and alignment is simplified. And, substantial hazards, inherent in prior apparatus and procedures which required bringing drill string sections to the rotary drive for coupling, are eliminated.

Apparatus embodying the invention will include: some form of superstructure, such as the frame of the preferred embodiment, which will be generally vertically oriented when erected for drilling; some form of means for rotating drill string, such as the rotary table of the preferred embodiment; some form of support for the rotary drive assembly, such as the carriage assembly of the preferred embodiment, which can be supported for up and down movement in relation to the superstructure and permit the rotary drive assembly to pivot or turn about a generally horizontal axis. Method embodying the invention will include bringing the rotary drive assembly to a racked drill string section for coupling and then moving the rotary drive assembly and coupled section into drilling alignment, and removal of drill string by reversing these steps. In addition, hydraulic lift means extending between the mast or its base and the carriage assembly means are flexibly or universally connected thereto in a manner enabling the use of relatively lightweight and flexible masts.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a generally perspective view of one preferred form of the apparatus shown supporting a drill string which is depending therefrom and extending into a hole in the earth.

FIG. 2 is a side elevation view on a somewhat reduced scale of the apparatus shown in FIG. 1, but

with the rotary table moved, or pivoted, to the position for adding or removing sections of drill pipe.

FIG. 3 is a fragmentary top plan view,. partially in section, showing a portion of the carriage means and means for rotating the rotary table relative thereto.

FIG. 4 is a sectional view of the pivot means'taken generally along line 4-4 of FIG. 3.

FIG. 5 is a top plan view, partially in section, of the carriage means and the rotary table supported thereby.

FIG. 6 is a cross-section of the rotary drive means taken generally along line 6-6 of FIG. 5.

FIG. 7 is a longitudinal sectional view, partially fragmented, showing the construction of one of the thrust cylinder assemblies.

FIG. 8 is a partial view, similar to FIG. 7, of the other thrust cylinder assembly.

FIG. 9 is an isolated isometric view of the support means for connecting the thrust cylinders to the carriage means.

FIG. 10 is a side elevation view showing the drill frame of the apparatus tilted at an angle such that the drilling axis of the drill frame diverges from the vertical.

DESCRIPTION OF THE PREFERRED EMBODIMENT The embodiment of the invention presently preferred by the inventor includes a drill frame generally designated by the numeral 11 and is comprised of a pair of generally upright trussed guide masts 12 connected at their upper ends by a pair of transverse bars 13. The lower ends of masts 12 are connected to and supported by an upper base 14 which is pivotally connected to lower base 15 by means of pin 20 and lug 21, the latter of which is attached to base 15, as shown in FIGS. 1, 2 and 10.

The drilling axis 35 of the drill frame is generally parallel with the longitudinal axes of the masts 12. Means are provided for tilting the drilling axis 35 of the drill frame relative to the horizontal by as much as 30, as shown in FIG. 10. One end of each side of upper base 14 is provided with a pair of upstanding lifting arms 17 having a plurality of longitudinally spaced pin holes 18. Pin holes 18 are adapted to receive a pin 22 which is adapted for passage through the upper end of a turnbuckle type jack screw 24, the lower end of which is supported by another pin passing through a pair of lugs 25 mounted on lower base 15.

Each pair of lifting arms 17 is provided with two vertically spaced connector lugs 27 and 28 which are arranged for connection to the upper end of piston rod 30, which is operated by hydraulic jack cylinder 31, the lower end of which is pivotally connected to another lug 32 mounted on lower base 15.

The lifting or tilting means is arranged such that, during operation thereof from the position shown in FIG. 1 to the position shown in FIG. 10, the upper ends of jack screws 24 are disconnected and, thereafter, hydraulic fluid is applied to hydraulic cylinders 31 to thereby effect partial raising of upper base 14 relative to lower base 15. Thereafter, the upper ends of jack screws 24 may be positioned in an intermediate hole 18, which will thereby support the upper base 14 in the partially raised position. Thereafter, piston rod 30 can be disconnected from connecting lug 27 and connected to connecting lug 28, after which hydraulic cylinder 31 may be actuated again to complete the raising action, and the upper end of jack screw 24 can then be connected in the lowermost position or hole 18 of tilting arms 17, as shown in FIG. 10. The apparatus is designed to accommodate a tilt of up to 30 and, by mounting base on an inclined support, the drilling axis of the drill frame can be angled up to 45 from perpendicular. The drilling axis is generally designated by the numeral 35 in FIGS. 2 and 10.

The apparatus invention also includes carriage means mounted for generally up and down movement on frame 11. These carriage means conveniently include a pair of yokes 41, each of which is mounted adjacent one of the guide masts 12 for up and down movement with respect thereto. Each of the yokes 41 has attached thereto a pair of guide shoes 42, each of which is arranged for slidingly engaging one side of a mast 12 for up and down movement therealong. Bearing type interfaces may be provided for the guide shoes to facilitate such sliding movement. As best shown in FIG. 3, each of the yokes 41 has an axletree 44 fixedly attached to it, as by bolts 45, the purpose of which will be explained hereinafter.

As best shown in FIGS. 1 and 9, each of the yokes 41 has rigidly attached thereto and extending upwardly therefrom a generally tubular support member 48 having an enlarged upper portion 49, which portion is provided with an annular lower bearing plate 50 and a similar upper annular bearing plate 51. Tubular support member 48 and enlarged portion 49 are generally arcuate shaped in cross-section, so as to receive and be connected to means for moving the carriage means generally up and down relative to drill frame 11, which means will now be described.

The movement means for moving the carriage means generally up and down relative to the drill frame 11 is preferably in the form of a pair of thrust cylinder assemblies 53, shown generally in FIG. 1 and in greater detail in FIGS. 7 and 8, each of which shows one of said pair. Referring now to FIG. 7, one of the thrust cylinder assemblies includes a cylinder barrel 54 which is closed at its upper end and which is provided at its lower end with a cap 55 having an aperture therein through which cylinder rod 56 extends downwardly. Cap 55 supports a stop tube 57 which extends upwardly therefrom and limits the extent of extension of rod 56 relative to cylinder barrel 54.

Flexible means are provided for connecting cylinders 53 to the carriage means heretofore described. These flexible means conveniently take the form of ball and socket connections or ball joint means, one of which is comprised of a ball portion 59 provided intermediate the ends of cylinder barrel 54 arranged for support in the race formed by ball bushing 60. In the assembled condition, ball bushing 60 is adapted for fitting in the enlarged portion 49 of tubular support member 48, heretofore described. The other connection includes a ball housing 66 connected to upper base 14, which in turn supports a ball bushing 67 which provides a race for a ring-shaped ball member 68 which is held in place on the lower end of cylinder rod 56 by lock nut 69 threadably connected to the lower end of cylinder rod 56. The flexible connection provided by these ball and socket assemblies prevents malfunctioning which might otherwise occur if drill frame 11 were subjected to twisting as a result of substantial torque forces that are usually encountered in drilling large diameter boreholes, and thereby permits continued operation of the thrust cylinder assemblies, sincethe flexible connection permits cylinder barrels 54 and cylinder rods 56 to maintain proper and perfect alignment during such twisting motion, if it should occur.

The upper end of cylinder rod 56 is connected to a cylindrical piston 63 which is arranged for sealing and sliding movement up and down inside cylinder barrel 54. Piston 63 is held in place on the end of rod 56 by rod retainer nut 64, in conventional manner. Cylinder rod 56, in the embodiment shown in FIG. 7, is generally tubular in shape. In addition, an annular space is provided between the internal surface of cylinder barrel 54 and the external surface of cylinder rod 56 so as to provide a space for the application of hydraulic fluid in conventional manner.

The upper end of cylinder barrel 54, shown in FIG. 7, is provided with aperture 71 which communicates with inlet and outlet connector 72, which is arranged for connecting to a flexible hydraulic line connected to the upper barrel of thrust cylinder assembly described in FIG. 8. Hence, the introduction of fluid into the cylinder barrel 54 through the lower end of rod 56 drives cylinder barrels 54 of both FIGS. 7 and 8 upwardly relative to pistons 63. Since the lower end of cylinder rod 56 is fixed to upper base 14, the result is that such application of hydraulic fluid causes cylinder barrels 54 to be raised, carrying with them the carriage means, which has been heretofore described as being connected thereto by ball and socket means previously described. When pistons 63 contact stop tubes 57, the limit of the extension of cylinder rods 56 is reached.

In addition, the lower end of cylinder barrel 54 is provided with another aperture 75 which communicates with inlet and outlet connector 76, which is connected by a flexible line to a similar inlet on the thrust cylinder assembly shown in FIG. 8. Hydraulic fluid flowing into that part of barrels 54 below pistons 63 through connector 76 causes retraction of cylinder rods 56 into cylinder barrels 54 and, hence, lowering of the carriage means connected thereto. Hence, by appropriate alternate injection and release of hydraulic fluid pressure through rods 56 the hydraulic thrust cylinder assemblies may be extended and retracted as desired and the carriage means raised and lowered accordingly.

It should be noted that the other of the hydraulic thrust cylinder assemblies shown in FIG. 8 is identical with the embodiment shown in FIG. 7, except that the upper end of cylinder rod 79 is solid, or otherwise closed, and is provided with transverse inlet and outlet ports 80 which communicate between the interior of rod 79 and the exterior thereof. This arrangement of cylinder rod 79 permits the application of hydraulic fluid upwardly therethrough from the lower end thereof and out through ports 80, to thereby urge piston 63 upwardly, to thereby retract cylinder rod 79, as described above. It is to be understood that the thrust cylinder assembly shown in FIG. 8 has an aperture and connector which are identical to aperture 75 and connector 76 of the assembly shown in FIG. 7. Hence, application of hydraulic fluid through ports 80 I nuvm n flows through the connectors 76 and apertures 75 to effect retraction of the pistons in both cylinder assemblies.

The apparatus of this invention also includes rotary drive means supported by the carriage means for rotating a drill string. This drive means is conveniently in the form of a rotary table assembly carried by traveling rotary drive housing 85 which is supported by the carriage means, as will be described hereinafter. As best shown in FIGS. 5 and 6, the rotary drive means includes four hydraulic motors 86, each of which is connected by hydraulic lines to a suitable source of pressurized hydraulic fluid for operation thereof. Each of the hydraulic motors 86 is connected through a reduction gear box 87 for rotation of a drive shaft 88, which is supported by a pair of bearings 89 mounted in rotary body 90. Each shaft 88 has mounted thereon for rotation therewith between bearings 89 a pinion gear 94 which is arranged for meshing with and rotating bull gear 95 which is splined or otherwise keyed, as by key 96, to rotary quill 100.

Quill 100 is supported for rotation in rotary body 90 by a lower thrust bearing 101 and an upper thrust bearing 102. The lower end of rotary quill 100 extends out through an annular opening 103 provided in the lower end of rotary body 90. In addition, rotary quill 100 has a connecting flange 105 attached thereto, as by threadedbolts 106. Flange 105 is adapted for connection to and supporting a connector sub 107 having an upper flange 108 which is arranged for connection to flange 105 by threaded bolts. 109. The other end of connector sub 107 is provided with a similar flange for connection to sections of drill pipe, as will be explained hereinafter.

The upper end of rotary quill 100 is arranged for rotation inside of swivel cylinder 113 which is connected to and supported by rotary body 90 and which is provided with packing 114 to provide a fluid-tight swivel connection with gooseneck connector 115, which is attached to rotary body 90 and arranged for fluid communication with the internal bore of rotary quill 100, as shown in FIG. 6. Gooseneck connector- 115 and rotary quill 100 are so arranged that drilling fluid may be pumped therethrough and through the drill string to effect circulation of a drilling fluid to aid .in the drilling operations when required.

Rotary body 90 may also be provided with a lube pump assembly 117 to facilitate lubrication of the rotary drive means thus described. It should also be understood that hydraulic motors 86 and drive assemblies associated therewith are arranged such that rotation of rotary quill 100 may be in either direction.

The invention also includes means connected to the heretofore described carriage means for moving the heretofore described rotary drive means relative to the carriage means to thereby move the rotary axis of the rotary drive means relative to the drill frame or relative to the drilling axis of the drill frame. This moving means is conveniently in the form of pivot means which will now be described. Referring now in particular to FIGS. 3, 4 and 5, it will be seen that each of the heretofore described pivot axletrees 44 has fixedly mounted thereabout and spaced intermediate the ends thereof, a

sprocket 120, over which is trained an endless drive chain 121.

In addition, traveling rotary drive housing 85, heretofore described, is arranged for rotation on pivot axletrees 44 by a pair of bearing bushings 123 at each end thereof. Further, means are provided for causing rotation of rotary drive housing about axletrees 44 and include the aforesaid sprockets 120 and drive chain 121. Each drive chain 121 is arranged for running over and engagement by a pair of drive sprockets 124, each of which is mounted for rotation with a shaft 125 which is journaled in a portion of rotary drive housing 85. Each of the shafts 125 is arranged for rotation by a pinion gear (not shown) which is arranged for rotation in the oppositedirection by a pair of cylinders 127 forming rack gears arranged for engagement of such pinion gears.

Hence, by operation of the cylinders 127, drive sprockets 124 may be rotated in either direction, thereby facilitating or causing the rotation of drive housing 85, and hence the drive assembly on axletrees 44. It is to be understood that the just described cylinders 127 and associated rack and pinion gears are of the type sold under the trademark FLO-TORK, marketed as a Rotary Hydraulic Actuator model No. 30,000, and manufactured by FLO-TORK Division of Allen Electric and Equipment Company of Orville, Ohio, USA. It is to be understood that other move mentor pivot means may be used to effect this pivoting movement of rotary drive housing 85. During such pivoting action, the rotary axis of the rotary drive means, which is designated by the numeral 128 in FIGS. 2 and 6, moves through an are which fallsin a plane which is generally perpendicular with the horizontal, which arc is generally shown, for example, by the numeral 129 in FIG. 2.

It is to be understood that hydraulic fluid is supplied to the various hydraulic fluid requiring units heretofore described by appropriate hydraulic lines connected to suitable hydraulic pressure sources and relief means through an operators station 133, shown in FIG. 1, having a standard control panel 134.

During operation of the apparatus, a pipe rack, such as pipe rack 137 shown in FIG. 2, may be provided, which rack maybe provided with pipe carrier 138 having two pairs of fingers 139 for supporting a section of drill pipe, such as section 140. Section 140 is shown having flange type joints at each end which are arranged for connection, as by bolts 141, to sub connector 107, as shown in FIG. 2. One advantage of flange type connections is that they can accommodate rotation of the drill string in either direction and permit easier connection and disconnection than might be true of certain threaded connections where terrifically large torque forces are involved, as is true in large diameter shaft drilling.

However, in some situations, it may be desirable to have threaded couplings for the drill pipe, in which event sub 107 can be provided with a conventional box end which is arranged to mate with the pin end of a section of drill pipe supported on fingers 139. In this event, it is preferable to have fingers 139 arranged to clamp the section of drill pipe to prevent rotation thereof. In this manner, make-up and breakout of the connection can be made by operation of the rotary drive means heretofore described.

In operation, the apparatus may be positioned in the manner generally shown in FIG. 1, where a drill string comprised of a plurality of sections 140 of drill pipe is suspended from connector sub 107, with the drill string depending into the borehole.

When it becomes desirable to add another length of drill pipe 140, slip assembly 141, which may be mounted on upper base 14, can be closed, thereby supporting the drill string. Thereafter, the flange coupling can be disconnected from connector sub 107. At this point rotary drive housing 85 is raised and rotated as described. The rotary drive means is thus moved to the position shown in FIG. wherein the rotary axis 128 of the rotary drive means and, hence, sub 107 are caused to move about a generally horizontal axis and through a generally vertical are 129 to the position shown in FIG. 2. Then another section of drill pipe 140 may be corrected to sub 107, after which rotary drive housing 85 is rotated and raised back to the drilling position and the lower end of the new section of pipe 140 added to the upper end of the drill string.

Conversely, when it is desirable to remove a section of drill pipe from the drill string, the operation is reversed. Hence, it will be seen that the pivot means for rotating the rotary drive means reduces reduces the cost and hazards otherwise present where sections of drill pipe are added to or removed from the drill string. It reduces the amount of pipe handling equipment required, and sections of drill pipe are never required to be suspended in the drill frame separate and apart from the drill string, thereby greatly enhancing safety and operating procedures. Moreover, in those instances where it is desirable to use threaded drill pipe, the rotary drive means can be used for purposes of make-up and break-out, as heretofore described.

Moreover, when it is desirable to drill a borehole at an angle, the drill frame can be tilted as shown in FIG. 10 and as heretofore described. Further, lower base can also be mounted on a sloping surface to increase the angle of the drilling axis up to 45. The apparatus can be used to drill a pilot hole downwardly and thereafter a larger bit can be attached to the drill string and a raise hole drilled upwardly. It will thus be apparent that the art has been provided with a very greatly improved drilling apparatus and method which is simple of operation and construction. Other modifications and alternate embodiments will be apparent to those skilled in the art in view of the foregoing description.

What is claimed is:

1. In apparatus for drilling earth formations, the improvement comprising the combination of:

frame means including a base;

carriage means secured to the frame means for selected upward or downward movement of a drill P P rotary table means carried by the carriage means to rotate the drill pipe;

hydraulic cylinder means having a cylinder barrel and a cylinder rod, one of which being connected with the carriage means and the other being connected with the frame means to move the carriage means up or down; universal movement means connecting the cylinder Farrel and cylinder rod to the carria ge mea s and rame means to enable lateral or s ewed exmg thereof. 2. In apparatus for drilling earth formations, the improvement comprising the combination of:

frame means including a base; 5 carriage means secured to the frame means for selected upward or downward movement of a drill pipe; rotary table means having a cylinder barrel and a cylinder rod, one of which being connected with the carriage means and the other being connected with the frame means to move the carriage means up or down; ball joint means used for connecting the cylinder barrel and cylinder rod to the carriage means and frame means to enable universal movement thereof and lateral or skewed flexing of the frame means relative to the carriage means. 3. In apparatus for drilling earth formations, the improvements comprising the combination of:

frame means including a base; carriage means secured to the frame means for selected upward or downward movement of a drill P p rotary table means carried by the carriage means to rotate the drill pipe; hydraulic cylinder means having a cylinder barrel and a cylinder rod, one of which being connected with the carriage means and the other being connected with the frame means to move the carriage means up or down; universal movement means used for connecting the cylinder barrel and cylinder rod to the carriage means and frame means to enable lateral or skewed flexing thereof; and means for pivoting said rotary table means to move the rotational axis of the drill pipe relative to said carriage means. 4. In apparatus for drilling earth formations, the improvements comprising the combination of:

frame means including a base; carriage means secured to the frame means for selected upward or downward movement of a drill P p rotary table means carried by the carriage means to rotate the drill pipe; hydraulic cylinder means having a cylinder barrel and a cylinder rod, one of which being connected with the carriage means and the other being connected with the frame means to move the carriage means up or down; ball joint means used for connecting the cylinder barrel and cylinder rod to the carriage means and frame means to enable universal movement thereof and lateral or skewed flexing of the frame means relative to the carriage means; and means for pivoting said rotary table means to move the rotational axis of the drill pipe relative to said carriage means.

"mm" "Al UNITED STATES PATENT AND TRADEMARK OFFICE Certificate Patent No. 3,695,363 Patented October 3, 1972 Joseph L. Kelly, Jr.

Application having been made by Joseph L. Kelly, J r., the inventor named in the patent above identified and Hughes Tool Company, Houston, Texas, a

corporation of Delaware, the assignee, for the issuance of a certificate under the provisions of Title 35, Section 256, of the United States Code, adding the names of Lee Roy Hodge and John F. Bryan, Jr. as joint inventors, and a showing and proof of facts satisfying the requirements of the said section having been submitted, it is this 31st day of January 1978, certified that the names of the said Lee Roy Hodge and John F. Bryan, Jr. are hereby added to the said patent as joint inventors with the said Joseph L. Kelly, Jr.

FRED W. SHERLING,

Associate Solicitor. 

1. In apparatus for drilling earth formations, the improvement comprising the combination of: frame means including a base; carriage means secured to the frame means for selected upward or downward movement of a drill pipe; rotary table means carried by the carriage means to rotate the drill pipe; hydraulic cylinder means having a cylinder barrel and a cylinder rod, one of which being connected witH the carriage means and the other being connected with the frame means to move the carriage means up or down; universal movement means connecting the cylinder barrel and cylinder rod to the carriage means and frame means to enable lateral or skewed flexing thereof.
 2. In apparatus for drilling earth formations, the improvement comprising the combination of: frame means including a base; carriage means secured to the frame means for selected upward or downward movement of a drill pipe; rotary table means having a cylinder barrel and a cylinder rod, one of which being connected with the carriage means and the other being connected with the frame means to move the carriage means up or down; ball joint means used for connecting the cylinder barrel and cylinder rod to the carriage means and frame means to enable universal movement thereof and lateral or skewed flexing of the frame means relative to the carriage means.
 3. In apparatus for drilling earth formations, the improvements comprising the combination of: frame means including a base; carriage means secured to the frame means for selected upward or downward movement of a drill pipe; rotary table means carried by the carriage means to rotate the drill pipe; hydraulic cylinder means having a cylinder barrel and a cylinder rod, one of which being connected with the carriage means and the other being connected with the frame means to move the carriage means up or down; universal movement means used for connecting the cylinder barrel and cylinder rod to the carriage means and frame means to enable lateral or skewed flexing thereof; and means for pivoting said rotary table means to move the rotational axis of the drill pipe relative to said carriage means.
 4. In apparatus for drilling earth formations, the improvements comprising the combination of: frame means including a base; carriage means secured to the frame means for selected upward or downward movement of a drill pipe; rotary table means carried by the carriage means to rotate the drill pipe; hydraulic cylinder means having a cylinder barrel and a cylinder rod, one of which being connected with the carriage means and the other being connected with the frame means to move the carriage means up or down; ball joint means used for connecting the cylinder barrel and cylinder rod to the carriage means and frame means to enable universal movement thereof and lateral or skewed flexing of the frame means relative to the carriage means; and means for pivoting said rotary table means to move the rotational axis of the drill pipe relative to said carriage means. 